DC`s Superman Unlimited comic series, written by Dan Slott and illustrated by Rafael Albuquerque, will debut on May 21. The series kicks off with a Kryptonite asteroid creating a global arms race for Green K, tipping the power balance in Metropolis. Superman must form new alliances to survive.

The comic is part of DC`s `Summer of Superman` initiative, which also includes titles starring Superboy, Supergirl and more.

A free `Zero Issue` prelude willbe available on May 3 for Free Comic Book Day.